Heretofore, as a method for preparing an aromatic aldehyde compound from an aromatic methyl alcohol compound, there have been well known, for example, a method of oxidizing a primary alcohol by using a metal oxide such as manganese oxide and pyridinium chlorochromate (PCC), etc. (for example, see Non-Patent Literature 1 and Non-Patent Literature 2.) or a reaction of Swern oxidation, etc. (for example, see Non-Patent Literature 3.). However, these reactions involve problems for carrying out the methods industrially because the reaction is carried out by using a metal reagent having high toxicity, or wastes occurs such as dimethylsulfide which accompanies bad smell after termination of the reaction so that environmental load is large.
On the other hand, a method of utilizing hydrogen peroxide has attracted attention in recent years because handling of hydrogen peroxide is easy, it can be decomposed to harmless water after the reaction, and further it is inexpensive (for example, see Patent Literature 1.).    [Patent Literature 1] JP H11-158107A    [Non-Patent Literature 1] Organic Letters, Vol. 5, 4725 (2003)    [Non-Patent Literature 2] J. Org. Chem., Vol. 69, 1453 (2004)    [Non-Patent Literature 3] Tetrahedron, Vol. 34, 1651 (1978)